Method for calculating near surface water vapor flux under local winds on Mars

Surface flow and water transport models of a northern small scale region on Mars have been developed with two main objectives, (1) to locally resolve water vapor transport in a shallow regolith, and (2) to introduce a method for calculating water vapor flux to the atmosphere by means of a non-dimensional interfacial Sherwood number. This number can be used to provide improved boundary conditions for atmospheric general circulation models. The near surface atmospheric flow and water transport models were three dimensional, capable of resolving complex terrain geometries, and included a layer of porous regolith. The models were used to simulate two different local atmospheric flows, the near surface thermal convection caused by early morning solar heating, and horizontal dry winds. Using these models, analyses were performed to study the effects of several parameters on the water transport process. For the simulations in this study, the NASA Phoenix Mars Lander landing site was selected. Variable parameters were regolith thickness, ambient pressure and temperature, imposed wind velocity and surface temperature. Results of the numerical simulations were summarized by means of the interfacial Sherwood number that can be used to readily calculate water flux from the regolith to the atmosphere.